1. Field of the Invention
This invention pertains to improvements in multilayer printed circuit or wiring boards, and, more particularly, to improvements in interconnections between multilayer printed circuits or wiring boards or the like, and to methods for making same.
2. References
"Button Connectors-Solderless, Low-Thermal Rise Interconnect For High-Speed Signal Transmission", MacCorquodale, Connection Technology, January, 1990, pp. 25-28, shows a button connecter for interconnection between multilayer printed circuit boards. The button connector is essentially a wad of crumpled wire, the cylindrical button being a mass of fine, springy, highly conductive wire that is fitted into a substrate through-hole by compression, thus limiting the necessity of solder. The dielectric substrate boards, loaded with the buttons, are placed between the circuit boards or components to be interconnected and clamped together.
U.S. Pat. No. 4,967,314 to Huggins, III shows the construction of a circuit board. A high density multi-level printed wiring board is disclosed having interlevel electrical connections made by via interconnect holes which are drilled or punched through only those layers of the wiring board that separate the two layers containing the conductors which are to be connected. The holes are filled with a low-resistance silver-filled conductive epoxy.
U.S. Pat. No. 4,584,456 to Oodaira et al. shows a method for producing a resistor from insulating material by local heating. The resistor is formed by locally heating a layer of insulating material between conductors to convert the heated material into a first resistor element. A second resistor element is formed to contact the first resistor element while measuring the resistance between the conductors, until a desired resistor composed of the first and second resistor element and having a predetermined resistance value is obtained.
U.S. Pat. No. 5,003,693 to Atkinson et al. shows a method for manufacturing electrical circuits within a carrier. The method provides an electrical circuit wherein a carrier, which is a film of insulating plastic material with a circuit pattern thereon, is supported in a mold and a molding material is applied by the application of heat and pressure to provide a substrate having a circuit embedded in or within a three-dimensional surface of the molded substrate.
U.S. Pat. No. 4,694,138 to Oodaira et al. shows a method of forming a conductive path within an insulated composition. The conductive path is formed by providing an insulating substrate having a surface region which is formed of an insulating composition. The insulating composition contains an organic polymeric material and at least one metal source. The surface region of the substrate is selectively heated along a predetermined pattern, thereby decomposing and evaporating the organic polymeric material at the heated portion and welding the metal in the heated portion so as to form a conductor path formed of metal.
U.S. Pat. No. 4,912,288 to Atkinson et al. shows a method of providing an electrical circuit molded within an insulated plastic surface. The method provides an electrical circuit on a surface of a three-dimensional shaped substrate of insulating plastic material, molded by the application of heat and pressure, so that the circuit is embedded in or within a surface of the molded substrate.
U.S. Pat. Nos. 4,841,099 and 4,970,553, to Epstein et al. and Orlowski et al., respectively, both assigned to the assignee of the present application show electrical components having conductive paths. A three-dimensional electrical component, having a first side and a second side formed from an electrically insulating polymer matrix capable of heat conversion to an electrically conducting polymer matrix, has at least one passageway from the first side to the second side having a tapered wall configuration with constantly changing cross-section of the passageway from the first side through the passageway to the second side and an electrically conducting path between the first side and the second side formed by the in situ heat conversion of the walls. The heat conversion of the electrically conductive paths are preferred to be completed by a laser.